Throttle valve control device for an internal combustion engine

摘要

A throttle valve control device for an internal combustion engine is obtained which has an improved sector gear 20 capable of suppressing inclinations of tooth surfaces 22a of its resin teeth 22 due to shrinkage of a resin upon hardening thereof at the time of insert molding. The throttle valve control device includes a motor 2 and the sector gear 20 operatively connected with the motor 2 for driving a shaft 8, on which a throttle valve 20 is fixedly mounted, by means of power transmitted thereto from said motor. The sector gear 20 has a sector-shaped rigid core member 21, and a resin molded portion 23 with the teeth 22 formed on the core member 21 by insert molding. The core member 21 has a support portion 24 with a curved surface 24a formed to extend along bottoms 22b of the teeth 22 and project in an axial direction as well.